Systems for servicing and maintaining aircraft, especially large modern "heavy" aircraft such as wide-body jets, generally include landing gear maintenance elevators which operate in wells located in the maintenance hangar floor. Each maintenance elevator is constructed to support the weight of one of the landing gear trucks of the aircraft. Typically, the aircraft is wheeled into the maintenance hangar and oriented so that each of the landing gear trucks is supported by a respective one of the elevators. Thereafter, the elevators can be controllably raised and lowered to facilitate maintenance and repair of the landing gear trucks and other components of the aircraft, such as the engines.
Aircraft maintenance elevation systems as currently known in the prior art possess certain deficiencies which detract from their overall utility. Foremost of these deficiencies is the inability to simultaneously raise and lower the elevator platforms which are typically adapted only to be independently controlled. As will be recognized, due to the tremendous weight of the aircraft and need to maintain the same in a substantially level orientation during the raising and lowering thereof, the independently controlled elevators must be moved in succession in very small increments, thus making the lifting and lowering procedure both a lengthy and tedious process. Though U.S. Pat. No. 4,889,202 (issued to Born on Dec. 26, 1989) discloses an aircraft maintenance elevation system wherein the elevator platforms may be independently or simultaneously raised and lowered, the drive motors included in this system are not electrically connected to each other in a manner allowing the simultaneous control of the elevator platforms to be effected by a single remote control unit. Additionally, this as well as other prior art aircraft maintenance elevation systems do not include a monitoring system associated with each of the elevator platforms which compares the relative positions of the elevator platforms to each other during the simultaneous raising and lowering thereof for purposes of preventing any substantial misalignment between the elevator platforms (i.e., movement of the top surfaces of the platforms out of co-planar relation to each other).
A further deficiency associated with prior art aircraft maintenance elevation systems is the lack of an auxiliary drive system associated with each of the elevator platforms which facilitates the movement of a respective elevator platform back to floor level in the event of the failure of the primary drive motors. Also absent from prior art aircraft maintenance elevation systems are safety devices which function to immediately deactivate the drive motors of any elevator platform which shifts out of parallel relation to the floor line, or experiences a failure in any one of the machine screw actuators used to raise and lower the same. The present invention overcomes these and other deficiencies associated with prior art aircraft maintenance elevation systems.